Much like the engine of a automobile, a subwoofer must go through a short but important process of break-in before it is run under harsh break-in process will ensure the subwoofer is able to perform as it has been designed to. This process involves subjecting the subwoofer to no more than low-to-medium volume levels for a number of hours in the enclosure.3-4 hours is generally sufficient for the subwoofer s suspension to loosen enough to prevent the voice coil(s) from overheating and causing failure. The break-in period is also effective in extending subwoofer life. Over-driving the woofer before it has been properly broken-in will usually result in premature failure and poor performance.